Jet pump assembly



OCt- 26, 1965 c. D. RAMSDEN ETAL 3,213,807

JET PUMP ASSEMBLY Filed Sept. 20, 1963 2 Sheets-Sheet 1 H Ch l' NINVENTORS OHA RL E5 0. RA MSDE/V RUSSELL J. ROBERTSON ATTORNEYS JET PUMPASSEMBLY Filed Sept. 20, 1963 2 Sheets-Sheet 2 l TJ mi f gs f1 OO N 'loINVENTORS o0 CHARLES 0. RAMSDE/V I' lI/JSSELL J. RROBERTSON LL/AM G. FASE BY m 9*' M I THE/? ATTORNEYS United States Patent 3,213,807 JET PUMPASSEMBLY Charles D. Ramsden, Alameda, Russell J. Robertson, San Leandro,and William G. Fraser, Castro Valley, Calif., assignors to Pacific CoastEngineering Company, a corporation of California Filed Sept. 20, 1963,Ser. No. 310,317 7 Claims. (Cl. 10S-262) Our invention relates to a jetpump assembly and more particularly to one adapted for use in hydraulicdredging, and will be described in connection with such use.

In hydraulic dredging, operations are controlled from a barge. A diggingladder is adapted to be lowered from the barge to the point of dredging,where it terminates in a rotatable cutter head. The cuttings are carriedup through the suction line of an impeller pump installed 0n the barge,for disposal at some other location.

A jet pump may be fabricated to the suction line at the entrance theretoas disclosed in the patent to neveling, No. 1,759,490, where the cutterhead is driven by a drive shaft from the barge, and the suction line ofthe impeller pump is supported along side the shaft; or as analternative, the jet pump assembly may be included in an arrangementsuch as disclosed in the co-pending application of Ramsden et al. forDredging Equipment, Serial No. 211,493, led July 23, 1962, now PatentNo. 3,152,- 409, where the suction line is rotatably mounted andperforms the added function of a drive shaft for the cutter head.

The jet pump assembly of the present invention is adaptable for use ineither of the foregoing types of installations.

Among the objects of our invention are:

(1) To provide a novel and improved jet pump assembly;

(2) To provide a novel and improved jet pump assembly adaptable for usein hydraulic dredging equipment;

(3) To provide a novel and improved jet pump assembly which may bereadily and economically serviced;

(4) To provide a novel and improved jet pump assembly which caneiciently pump liquid contaminated with solid matter;

(5) To provide a novel and improved jet pump assembly of greatstructural simplicity and ruggedness; and

(6) To provide a novel and improved nozzle construction for a jet pumpassembly.

Additional objects of our invention will be brought out in the followingdescription of a preferred embodiment of the same, taken in conjunctionWith the accompanying drawings wherein:

FIGURE 1 is a side View, partly in section, of the lower end of adigging ladder of a hydraulic dredge, and depicting therein, theinstallation of a jet pump assembly of the present invention;

FIGURE 2 is a plan View of the apparatus of FIG- URE 1;

FIGURE 3 is a longitudinal view, partly in section, of the jet pumpassembly of the present invention;

FIGURE 4 is an enlarged fragmentary view of that portion of the jet pumpassembly of FIGURE 3 depicting details of construction of each of thenozzles therein; and

FIGURES is a side view depicting a different arrangement of a diggingladder of a hydraulic dredge, wherein the cutter head is driven by thesuction line, functioning as a drive shaft, and depicting the manner ofinstallation therein, of the jet pump assembly of the present invention.

Referring to FIGURE 1 of the drawings, the jet pump assembly 1 embodyingthe features of the present invention, is coupled at one end to thesuction line 3 of the rice power pump, while its intake end is flowcoupled with the cutter head 5 by means of one or more coupling sections7, 9 etc., terminating in an opening 15 provided in a tting 17, in thehub of which is a bearing 19 for the shaft 21 of the cutter head. Thesuction line 3, jet pump assembly 1, and drive shaft 21 for the cutterhead, are supported by the framework of a digging ladder 25 which may beformed of longitudinal I-beams 27 connected by transverse beams 29.These transverse beams carry bearings 31 for the drive shaft 21 to thecutter head, and any suitable means 37 for supporting the suction line 3and jet pump assembly 1.

Extending laterally to either side of the digging ladder from the twoupper corner beams 27, are sheave mounting supports 41 for connectingthe swinging sheaves which are used to haul the dredge ladder to theleft and to the right, pivoting about the dredge stern to accomplishdredging operations.

Referring to FIGURES 3 and 4 of the drawing for details of the jet pumpassembly 1 of FIGURE 1, the same comprises an open end housing 45including an enlarged section 47, this enlarged section having end walls49, 51 With a main flow opening through each, and an outer wall 55 ispreferably cylindrical in character, and is provided with one or moreflanged openings 57 for connection to each, of a pressure line 61, whichin an installation of the character under description, would carry waterunder high pressure from a pressure pump on the barge, thus constitutingthe enlarged section a pressure chamber.

On the low pressure side of the housing, the pertinent end wall 51 ofthe enlarged section may be welded or otherwise atlixed to a cylindricalsection 65 of the housing 45, which terminates in a bolting flange 67.On the high pressure discharge side of the housing, a cylindricalsection 71 may may likewise be Welded to the proximate end Wall 49 ofthe pressure chamber, this cylindrical section however, being ofsomewhat larger diameter than the cylindrical section 65 on the intakeor low pressure side, to permit of installation of a jet sleeve 75, ofan internal diameter corresponding to that of the iirst cylindricalsection 65.

This jet sleeve is basically a cylinder adapted to be slipped throughthe discharge end of the housing 45, to abut against the proximate endof the cylindrical section 65 of the housing, and in that region of thesleeve lying within the enlarged section or pressure chamber 47 of thehousing and preferably adjacent the end Wall 49 thereof on the dischargeside, the sleeve is provided with at least one, and preferably aplurality of jets, which in the preferred form of the invention, takethe form of passageways 81 through the wall of the sleeve and having theproper characteristics for performing the function of jets. We havefound that most eicient functioning of these jets is realized when thecharacteristics of the passageways meet certain rather definiterequirements.

In FIGURE 4 of the drawings, we have attempted to depict the rathercritical nature of these characteristics. One of the most important ofthese requirements, is that the axis 83 of the passageway with respectto the longitudinal axis 85 of the housing should be closely controlledbetween 15 and 25 and may be stated as being of the order of 20. Thediameter of the jet passageway will depend on the type of installationto be serviced by the jet pump assembly, but the entrance to suchpassageway should be ared, with the upper edge portion of the entranceconforming to an arc 87 having a radius of curvature equal toapproximately one-half the diameter of the passageway, though a somewhatlarger radius of curvature could be tolerated.

The length of the jet passageway as measured between the diameter at thepoint of mergence between the upper entrance arc 87 and the cylindricalportion of the passageway, and the diameter at the lower edge 93 of theexit end of the passageway, should be approximately one-half of thediameter of the passageway. Preferably, the lower edge of the exit endof the jet passage is ground fiat to approximately one inch, whereuponthe length of the jet passage will be measured to this point.

To obtain the necessary length of jet passageways without undulythickening the walls of the jet sleeve, the sleeve is preferablyprovided with a wide rib 97 at the location of the jet nozzles, and forinstallation purposes, the proximate end wall 49 of the pressure chamberwill have a receiving opening such as to snugly receive this ribbedportion of the jet nozzle sleeve.Y

At the discharge end of the housing, the housing may be slightlyrecessed to receive a centering supporting ring 101 which may beremovably but snugly tted into position about the discharge end of thenozzle sleeve, following insertion of the sleeve to its proper positionin the housing. The jet nozzle sleeve 75 and supporting centering ring101 will be maintained in proper assembled position by the adjacentsection 1613 of the suction line, which is bolted to the housing at thispoint.

The simplicity and ruggedness of the jet pump assembly as thus describedwill become readily apparent. In operation, water at high pressure isdirected from the pressure pump on the barge, through the pressure lines61 to the pressure chamber 47, from where it will llow through the jetnozzles 81 at high velocity and create a region of low pressure adjacentthe exit end of the jet nozzles, which will serve to suck in Water withthe cuttings from the cutter head and discharge the same into thesuction line of the impeller pump, which may then take over to elevatesuch material to the barge where it may be disposed of as desired.

In FIGURE 5 of the drawings, we have illustrated a jet pump assembly ofthe present invention, adapted for use inv dredge equipment, wherein thesuction line of the impellei' pump performs the added function of adrive shaft for the cutter head.

The jet pump assembly will be similar to that of FIG- URE 3 previouslydescribed, except inV that the pressure chamber 47 will be rotatablymounted so that it may be held stationary while the rest of the jet pumpassembly may be rotated with respect thereto.

Toward this end, the cylindrical section 111 of the housing, on thedischarge side, extends to and slightly overlaps the cylindrical section113 of the housing on the intake side, and that portion spanning theregion of the pressure chamber, has openings 115 exposing the jetnozzlesr to high pressure liquid from the pressure chamber.

Where it overlaps the cylindrical section of the intake side of the pumpassembly, the cylindrical section 111 has welded thereto, an internalring 117 of suicient thickness to snugly receive the cylindrical section113 on the intake side of the pump assembly to which it may be welded.

In alignment with the ribbed portion of the jet nozzle sleeve, thecylindrical section of the housing has welded thereto, an internal ring119 adapted to snugly receive the jet nozzle sleeve 75 at this point.

The pressure chamber, unlike the pressure chamber of FIGURE 3, does notbecome an integral part of the jet pump assembly housing, in that theend walls 121 and 123 of the pressure chamber corresponding to the endwalls 49 and 51 of FIGURE 3, are, in this embodiment, not welded to thecylindrical sections of the housing as in the embodiment of FIGURE 3.Instead, these end walls are each provided with an enlarged opening of adiameter assuring substantial clearance between the rim of such openingand the outer surface of the cylindrical section 111 of the housing.

Such clearance space is sealed by a rotary seal involving a seal bearingring 127 surrounding the cylindrical section of the housing in alignmentwith each end wall 0f the pressure chamber, and an inwardly flanged seal129 of flexible material bolted to each end wall, with the inwardlydirected flange in pressure Contact with the proximate bearing ring 127.The inwardly directed flange of the sealing ring is of significance inthe present construction, in that the water entering the pressurechamber through the pressure lines from the pressure pump on the barge,being of greater pressure than the static pressure of the watersurrounding the jet pump assembly during a dredging operation, willdiscourage entrance of sediment and gravel or other foreign matter intothe pressure chamber via the rotary seals.

Because of the somewhat different construction of the overall housing ofthe jet pump assembly in the embodiment of FIGURE 5 under consideration,the manner of supporting the same from the digging ladder will besomewhat diiferent, in that the manner of support must permit ofrotation of the suction line along with the jet nozzle sleeve and thecoupling sections connecting the jet pump assembly to the cutter head.

Accordingly, the pressure chamber 47 which will be maintainedstationary, may be directly supported from proximate members of thedigging ladder, While the coupling sections and the suction line, whichare to rotate, are supported in bearings, such as bearing 131, suspendedfrom or otherwise supported by the members of the digging ladder.

In either embodiment of the invention described, the jet nozzles willtake the brunt of the wear. Being that these nozzles are formed in thenozzle sleeve, the entire set of nozzles may be replaced simply byremoving the old sleeve and replacing it with a new one and this can beaccomplished economically both as to time and labor.

From the foregoing description of our invention, it will be apparentthat the same fulfills all the objects thereof, and while we haveillustrated and described the invention in considerable detail, it willbev apparent that the same is subject to alteration and modificationwithout departing from the underlying principles involved, and weaccordingly do not desire to be limited in our protection to thespecific details illustrated and described, except as may benecessitated by the appended claims.

We claim:

1. A jet pump assembly comprising an open end housing including anenlarged section forming a pressure chamber having end walls, and anouter connecting wall,

said outer connecting wall having peripherally spaced openings forconnection of a pressure line to each, and av jet nozzle assemblyremovably kinstalled in said housing, said jet nozzle assembly includinga sleeve removably insertable through an end of said housing and adaptedto be supported therein,

said sleeve having a plurality of inwardly directed nozzles spacedcircumferentially thereabout in the region of said pressure chamber, toplace said nozzles in ilow communication with said pressure lineopenings,

each of said nozzles having its axis at an angle of the order of 20degrees to the longitudinal axis of said sleeve, and an effective lengthapproximately onehalf the diameter of the nozzle,

and means substantially sealing the nozzle region of the sleeve to saidpressure chamber.

2. A jet pump assembly comprising a pressure chamber having end wallswith a flow opening through each and an outer wall connecting said endwalls,

said outer connecting wall having an opening forconnection of a pressureline thereto,

a jet nozzle assembly removably installed in said pressure chamber, saidjet nozzle assembly including a sleeve removably insertable through anend of said pressure chamber and adapted to be frictionally supportedtherein,

said sleeve having at least one inwardly directed nozzle in lowcommunication with said pressure line opening,

and means providing for relative rotational movement between said jetnozzle assembly and said pressure chamber.

3. A jet pump assembly comprising a presusre chamber having end wallswith a ow opening through each and an outer wall connecting7 said endwalls,

said outer connecting wall having an opening for connection of apressure line thereto,

a jet nozzle assembly removably installed in said pressure chamber, saidjet nozzle assembly including a sleeve removably insertable through anend of said pressure chamber and adapted to be supported there- 1n,

said sleeve having at least one inwardly directed nozzle in llowcommunication with said pressure line opening,

and means providing for relative rotational movement between said jetnozzle assembly and said pressure chamber, said means including a rotarypressure seal means between each of said end walls and said jet nozzleassembly.

4. A jet pump assembly comprising an open end housing including anenlarged section forming a pressure chamber having end walls, and anouter connecting wall,

said outer connecting wall having peripherally spaced openings forconnection of a pressure line to each,

a jet nozzle assembly removably installed in said housing, said jetnozzle assembly including a sleeve removably insertable through an endof said housing and adapted to be supported therein,

said sleeve having a plurality of inwardly directed nozzles spacedcircumferentially thereabout in the region of said pressure chamber, toplace said nozzles in flow communication with said pressure lineopenings,

and means providing for relative rotational movement between said jetnozzle assembly and said pressure chamber, said means including each ofsaid end walls having an opening of a diameter to assure substantialclearance between said chamber Walls and the proximate wall of saidhousing,

and a rotary seal between each of said chamber walls and said proximatewall,

said rotary seal including a flexible sealing ring having an inturnedflange.

5. A jet pump assembly comprising an open end housing including anenlarged section forming a pressure chamber having end walls, and anouter connecting wall,

said outer connecting wall having peripherally spaced openings forconnection of a pressure line to each,

a jet nozzle assembly removably installed in said housing, said jetnozzle assembly including a sleeve removably insertable through an endof said housing and adapted to be supported therein,

said sleeve having a plurality of inwardly directed nozzles spacedcircumferentially thereabout in the region of said pressure chamber, toplace said nozzles in ow communication with said pressure line openmgs,

each of said nozzles having its axis at an angle of the order of 20degrees to the longitudinal axis of said sleeve, and an eective lengthapproximately one-half the diameter of the nozzle,

and means providing for relative rotational movement between said jetnozzle assembly and said pressure chamber, said means including each ofsaid end walls having an opening of a diameter to assure substantialclearance between said chamber walls and the proximate wall of saidhousing,

and a rotary seal between each of said chamber walls and said proximatewall,

said rotary seal including a flexible sealing ring having an inturnedflange.

6. A component for a jet pump assembly comprising a sleeve having atleast one inwardly directed nozzle integrally formed in the wallthereof,

said nozzle having an axis at an angle of the order of 20 degrees to thelongitudinal axis of said sleeve, and an effective length approximatelyone half the diameter of the passage through said nozzle.

7. A component for a jet pump assembly comprising a sleeve having aplurality of inwardly directed circumferentially spaced nozzlesintegrally formed in the wall thereof,

each of said nozzles having an axis at an angle of the order of 20degrees to the longitudinal axis of said sleeve, and an etective lengthapproximately one half the diameter of the passage through said nozzle.

References Cited bythe Examiner UNTED STATES PATENTS 129,977 7/ 72Milligan 103-260 334,597 1/86 Marsh 103-2'78 X 1,116,971 11/14 Barker103-262 2,582,069 1/52 Rose 10S-262 5 LAURENCE V. EFNER, Primm Examiner.

WARREN E. COLEMAN, Examiner.

1. A JET PUMP ASSEMBLY COMPRISING AN OPEN END HOUSING INCLUDING ANENLARGED SECTION FORMING A PRESSURE CHAMBER HAVING END WALLS, AND ANOUTER CONNECTING WALL, SAID OUTER CONNECTING WALL HAVING PERIPHERALLYSPACED OPENINGS FOR CONNECTION OF A PRESSURE LINE TO EACH, AND A JETNOZZLE ASSEMBLY REMOVABLY INSTALLED IN SAID HOUSING, SAID JET NOZZLEASSEMBLY INCLUDING A SLEEVE REMOVABLY INSERTABLE THROUGH AN END OF SAIDHOUSING AND ADAPTED TO BE SUPPORTED THEREIN, SAID SLEEVE HAVING APLURALITY OF INWARDLY DIRECTED NOZZLES SPACED CIRCUMFERENTIALLYTHEREABOUT IN THE REGION OF SAID PRESSURE CHAMBER, TO PLACE SAID NOZZLESIN FLOW COMMUNICATION WITH SAID PRESSURE LINE OPENINGS, EACH OF SAIDNOZZLES HAVING ITS AXIS AT AN ANGLE OF THE ORDER OF 20 DEGREES TO THELONGITUDINAL AXIS OF SAID SLEEVE, AND AN EFFECTIVE LENGTH APPROXIMATELYONEHALF THE DIAMTER OF THE NOZZLE, AND MEANS SUBSTANTIALLY SEALING THENOZZLE REGION OF THE SLEEVE TO SAID PRESSURE CHAMBER.